Pigment Mixtures Research Articles

Black, white, and grays: Are they colors, absence of color or the sum of all colors?

AbstractSometimes it is said that white is not a color but “the sum of all colors.” Surely this confusion comes from considering colors only those that appear in the spectrum. If these were the only colors, then magenta would neither be a color, nor do brown and other colors that do not have a specific wavelength, but are produced by a mixture of different wavelengths. Contradictorily, white often appears as “the absence of color.” When pigments are used on canvas or paper, white is the surface that remains unpigmented, unpainted, “uncoloured.” The same confusion often occurs with regard to black. Black is said to be “the sum of all colors” when a blackish stain is obtained from the mixture of various pigments. And black is said to be the “absence of color” when all light radiation is removed. The aim of this article is to argue that black and white are also colors, and so are grays. Because color is a visual sensation (product of the interaction of luminous radiation with pigmented objects and observers). “Pigment” and “color” are not synonymous; “light radiation” and “color” are not synonymous either. And just as we have red, green, blue, or yellow visual sensations, we also have visual sensations of white, black, or gray. This argument is supported by a survey where lay people and experts are asked about this issue, and by a bibliographical research that looks into texts and color order systems developed by theorists since the ancient times to nowadays.

Integrative Metabolomic and Transcriptomic Analyses Uncover Metabolic Alterations and Pigment Diversity in Monascus in Response to Different Nitrogen Sources.

ABSTRACTNitrogen in different chemical forms is critical for metabolic alterations in Monascus strains and associated pigment diversity. In this study, we observed that ammonium-form nitrogen was superior in promoting the biosynthesis of Monascus pigments (MPs) when compared with nitrate and organic forms. Moreover, with any nitrogen source, the production of yellow and orange pigments was highly synchronized but distantly related to red pigments. However, transcriptional analyses of MP gene clusters suggested a low contribution to MP accumulation, suggesting that MP-limiting factors were located outside the gene cluster. Our metabolomic analyses demonstrated that red pigment biosynthesis was closely related to intracellular amino acids, whereas orange and yellow pigments were associated with nucleotides. In addition, weighted gene coexpression network analyses (WGCNA) based on transcriptomic data showed that multiple primary metabolic pathways were closely related to red pigment production, while several secondary pathways were related to orange pigments, and others were involved with yellow pigment regulation. These findings demonstrate that pigment diversity in Monascus is under combined regulation at metabolomic and transcriptomic levels.IMPORTANCE Natural MPs containing a mixture of red, orange, and yellow pigments are widely used as food coloring agents. MP diversity provides foods with versatile colors and health benefits but, in turn, complicate efforts to achieve maximum yield or desirable combination of pigments during the manufacturing process. Apart from the MP biosynthetic gene cluster, interactions between the main biosynthetic pathways and other intracellular genes/metabolites are critical to our understanding of MP differentiation. The integrative multiomics analytical strategy provides a technical platform and new perspectives for the identification of metabolic shunting mechanisms in MP biosynthesis. Equally, our research highlights the influence of intracellular metabolic alterations on MP differentiation, which will facilitate the rational engineering and optimization of MP production in the future.

From Paris and Shanghai to Singapore: A Multidisciplinary Study in Evaluating the Provenance and Dating of Two of Liu Kang’s Paintings

This paper focuses on the dating and provenance of two paintings, Climbing the hill and View from St. John’s Fort by the prominent Singaporean artist Liu Kang (1911–2004). Climbing the hill, from the National Gallery Singapore collection, was believed to have been created in 1937, based on the date painted by the artist. However, a non-invasive examination unveiled evidence of an underlying paint scheme and a mysterious date, 1948 or 1949. These findings prompted a comprehensive technical study of the artwork in conjunction with comparative analyses of View from St. John’s Fort (1948), from the Liu family collection. The latter artwork is considered to be depicting the same subject matter. The investigation was carried out with UVF, NIR, IRFC, XRR, digital microscopy, PLM and SEM-EDS to elucidate the materials and technique of both artworks and find characteristic patterns that could indicate a relationship between both paintings and assist in correctly dating Climbing the hill. The technical analyses were supplemented with the historical information derived from the Liu family archives. The results showed that Climbing the hill was created in 1948 or 1949 on top of an earlier composition painted in Shanghai between 1933 and 1937. As for the companion View from St. John’s Fort from 1948, the artist reused an earlier painting created in France in 1931. The analytical methods suggested that Liu Kang used almost identical pigment mixtures for creating new artworks. However, their painting technique demonstrates some differences. Overall, this study contributes to the understanding of Liu Kang’s painting materials and his working practice.

Discovering the evolution of Jacques-Louis David\u2019s portrait of Antoine-Laurent and Marie-Anne Pierrette Paulze Lavoisier

Jacques-Louis David’s (1748–1825) iconic portrait of Antoine Laurent Lavoisier (1743–1794) and Marie-Anne Lavoisier (Marie-Anne Pierrette Paulze, 1758–1836) has come to epitomize a modern couple born of the Enlightenment. An analytical approach that combined macro-X-ray fluorescence with the examination and microanalysis of samples by Raman spectroscopy and scanning electron microscopy-energy dispersive X-ray spectrometry to investigate imprecise indications of changes to the composition observed by microscopy and infrared refectography allowed the visualization of a hidden composition with a high level of detail. The results revealed that the first version depicted not the progressive, scientific-minded couple that we see today, but their other identity, that of wealthy tax collectors and fashionable luxury consumers. The first version and the changes to the composition are placed in the context of David’s mastery of the oil painting technique by examining how he concealed colorful features in the first composition by using paint mixtures that allowed for maximum coverage with thin paint layers. The limitations of the analytical techniques used are also discussed. To our knowledge, this is the first in-depth technical study of a painting by J.-L. David.

Experimental and numerical analysis of solar still using Pyrex glass quantum dot in tropical climate

This study investigates the effect of using quantum dots (QDs) on the performance of solar still in the tropical climate of India. This article presents a new way to use QDs, which on absorbing solar energy increases water evaporation rate. Pyrex glass powder QDs are used in the solar still due to its high absorptivity value. An experimental setup of solar still with QD and without QD was developed, and a comparative analysis was conducted under the real outdoor environment in a tropical climate. The experimental results were also validated through mathematical modeling. The experiment was carried out by mixing Pyrex glass powder QDs with black paint and was coated on the basin and sidewalls of the solar still. Experiments were conducted for a depth of 0.02 m for solar still with QDs and without QDs. The results revealed that for 0.02 m of water depth and 1 m2 of basin area, the percentage increase in distillate output using Pyrex glass powder QDs is 29.36% experimentally and 29.94% theoretically. Furthermore, the net percentage increase in solar still efficiency by using Pyrex glass QDs is 74.74% experimentally and 61.03% theoretically. The study analyzed that all the experimental results are in good agreement with the theoretical analysis. The addition of Pyrex glass powder QDs and black paint mixture in the basin of solar still caused significant enhancement in the distillate output and solar still efficiency.

Double Helical Spiral Mixer

Recently in advance mixer and blender designs have contributed to the growing success of food companies, meeting their requirement for consistency and developing new products, with lowering production costs. This paper discusses both traditional and new specialty mixing technologies available to food manufacturers today. Phases and viscosity are used to classify different mixing categories. Sample applications are presented as well to illustrate certain processing challenges and the mixing technologies used to resolve them. In conventional method of mixing the metal oxide powder and vehicle mixing is perform on ‘Unidirectional Stirring Machine’. The stirrer of conventional machine rotates in only one direction which creates a particular flow pattern in the fluids. Hence the particles tend to stick to the walls of container owing to the centrifugal force rather than mixing thoroughly in mixture of paint, ultimately results into poor quality mixture of paints there by poor quality output of paint.

The combined use of SEM-EDX, Raman, ATR-FTIR and visible reflectance techniques for the characterisation of Roman wall painting pigments from Monte d\u2019Oro area (Rome): an insight into red, yellow and pink shades

The aim of this work has been the identification of the painter’s materials employed in the wall decoration of some destroyed buildings dating approximately between the first century B.C. and the first century A.D. This research originates from a previously started joined archaeological and analytical investigation concerning a varied group of findings that resulted from a rescue excavation performed by Soprintendenza Archeologica in the area of Monte d’Oro in Rome. The focus of this study progression has been directed to a numerous selection of monochrome red, pink and yellow-pigmented fragments. The analyses were performed by means of scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDX) combined with Raman and Fourier transform infrared (FTIR) spectroscopies; visible reflectance measurements have also been carried out and the relevance of this technique in such a kind of archaeological studies has been highlighted. Most attention has been given to the assessment of the performances of non-destructive techniques achieved by portable Raman, and visible reflectance instrumentation to test their diagnostic capabilities. In addition to the expected and well-known pigments such as cinnabar, red ochre, hematite for the reds and yellow ochre for the yellows, the study highlighted a diffuse use of mixed colours and in some cases the possible presence of overlapped painted layers and confirmed the presence of gildings. Among the mixtures of pigments, the most singular outcome concerns the pink fragments revealing the possible application of bone white, which seems to be rather uncommon as a pigment in Roman wall decorations.

Nonlinear Mixing Characteristics of Reflectance Spectra of Typical Mineral Pigments

Hyperspectral technology has been used to identify pigments that adhere to the surfaces of polychrome artifacts. However, the colors are often produced by the mixing of pigments, which requires that the spectral characteristics of the pigment mixtures be considered before pigment unmixing is conducted. Therefore, we proposed an experimental approach to investigate the nonlinear degree of spectral reflectance, using several mixing models, and to evaluate their performances in the study of typical mineral pigments. First, five mineral pigments of azurite, malachite, cinnabar, orpiment, and calcite were selected to form five groups of samples, according to their different mass ratios. Second, a fully constrained least squares algorithm based on the linear model and three algorithms based on the nonlinear model were employed to calculate the proportion of each pigment in the mixtures. We evaluated the abundance accuracy as well as the similarity between the measured and reconstructed spectra produced by those mixing models. Third, we conducted pigment unmixing on a Chinese painting to verify the applicability of the nonlinear model. Fourth, continuum removal was also introduced to test the nonlinearity of mineral pigment mixing. Finally, the results indicated that the spectral mixing of different mineral pigments was more in line with the nonlinear mixing model. The spectral nonlinearity of mixed pigments was higher near to the wavelength corresponding to their colors. Meanwhile, the nonlinearity increased with the wavelength increases in the shortwave infrared bands.

Analysis of the effect of stirrer and container rotation direction on mixing index (Ip)

The paper discusses the effect of the stirrer and container rotation direction on the mixing index (Ip). The chaos theory is the result of an in-depth study of various problems that cannot be answered by the two previous major theories, namely quantum mechanics and the theory of relativity. Effective mixing of the flow area does not depend on rapid stirring. This study uses a container with a double stirrer, camera, programmable logic controller, tachometer, 6 A adapter, and a computer. DC electric motor (25 V) for turning stirrers and housings. The diameter of the primary and secondary stirrers is Dp=38 mm and Ds=17 mm. The diameter of the container made of transparent plastic is Dw=160 mm and height is 170 mm. Primary stirrer rotation (np)=10 rpm, secondary stirrer rotation (ns)=22.3 rpm, and container rotation (nw)=13 rpm, the angular velocity of the container is Ww=360° while the angular speed of the primary stirrer is Wp=180°. The liquid consists of a mixture of water and paint (white). For dye, a mixture of water and paint (red) is used. For testing the Brookfield viscometer, the viscosity of the liquid and dye is used. The results showed that turning the stirrer in the opposite direction to the container, there will be stretching, bending, and folding around the stirrer, and the smallest mixing index was P2V-b (0.94). In addition, based on the mixing index value above, the highest mixing effectiveness level is obtained, namely: P2V-b, P2S-b, P2B-b, P2V-a, P2B-a, and finally P2S-a. The mixing index is inversely related to the effectiveness level. So the highest effectiveness level is given by the following treatment: 1. Variation rotation (between opposite rotating mixers), 2. Opposite rotation (stirrer rotation opposite direction to the container), 3. Unidirectional rotation (stirrer rotation in the direction of the container)

PRODUCTION OF FIBER AS AN INPUT MATERIAL FOR THE 3D PRINTING PROCESS

Additive manufacturing, also known as 3D printing, is the process of joining organic, ceramic, polymer, metal and others materials. Most often used as input material are the ABS and PLA plastics. A large number of plastic products is constantly generated by industry, which beckons the idea how to manufacture these products in more environmentally friendly way. This paper deals with the possibility of producing a 3D printing fiber from a granular PLA material Ingeo 2003D with the addition of a mixture of color powder pigment and fiber from the selected PLA material with a glass powder filler. The production was carried out using the FilaFab PRO EX350 device, which is designed for fiber extrusion for 3D printing technology. The aim of the experiment was the creation of new materials in the form of fibers and their mutual comparison in tensile tests with commercially available materials intended for 3D printing.

An Insight to the Composition of Pre-Hispanic Mayan Funerary Pigments by 1H-NMR Analysis.

The funerary rites of particular members of the pre-Hispanic Mayan society included the pigmentation of the corpse with a red color. In order to understand this ritual, it is first necessary to identify the constituents of the pigment mixture and then, based on its properties, analyze the possible form and moment of application. In the present approach, 1H-NMR analysis was carried to detect organic components in the funerary pigments of Xcambó, a small Maya settlement in the Yucatan Peninsula. The comparison of the spectra belonging to the pigment found in the bone remains of seven individuals, and those from natural materials, led to the identification of beeswax and an abietane resin as constituents of the pigment, thus conferring it agglutinant and aromatic properties, respectively. The 1H-NMR analysis also allowed to rule out the presence of copal, a resin found in the pigment cover from paramount chiefs from the Mayan society. Additionally, a protocol for the extraction of the organic fraction from the bone segment without visible signs of analysis was developed, thus broadening the techniques available to investigate these valuable samples.

Vehicle identification from automotive paints transferred in road accidents

Introduction Paint chips and smears represent the most common types of trace evidence resulting from vehicle-related incidents [1,2]. Analysis of these traces would ideally lead to the identification of the paint producer and ultimately of the vehicle in question [2]. Despite the chemical complexity of automotive paints, several reports showed this identification to be possible through the use Py-GC/MS, SEM-EDX, WDXRF, Raman and FTIR spectroscopy [1,3–5]. However, these studies were focussed on the analysis of each of the individual layers that compose the painting, making the analysis more complex, time consuming and dependent on highly specialised equipment. In the present work, we evaluated the discriminative potential of ATR-FTIR for the identification of paint producers, based on the analysis of the paint as a whole. Materials and methods Fragments of 6 different car paints obtained from the hood and lateral panels were milled and analysed through ATR-FTIR, both individually and as mixtures between pairs of paint Figure 1. Spectra were obtained between 450 and 4000 cm−1, with a resolution of 4 cm−1 and 16 accumulations. Figure 1. ATR-FTIR spectra of the isolated paints (top and bottom spectra), and of the mixtures at different ratios (middle spectra), where A) corresponds to a blue Volvo (A) and a red Renault (B); (B) to a blue Citröen (A) and a grey Skoda (B); (C) to a black Peugeot (A) and a grey Seat (B). Results The obtained results show the paint spectra to have considerable differences both in the number and intensity of IR bands. Furthermore, the mixtures’ spectra clearly show bands of both individual paints that are proportional, in intensity, to the ratio of each individual paint. Discussion and conclusions: These preliminary results show considerable differences between the FTIR spectra of the individual paints that propagate throughout the paint mixtures. This suggests that there are features in the ATR-FTIR spectra of automotive paints, as a whole that might be suitable predictors for the development of highly accurate predictive models.

Early wheat yield estimation at field-level by photosynthetic pigment unmixing using Landsat 8 image series

This paper presents a novel approach for estimating wheat yields based on estimated abundances of endmembers attributed to photosynthetic pigments, using Landsat 8 images acquired during maximum greenness. Endmembers within the wheat pixels are found using an unmixing algorithm then they are further optimized to maximize the predictive power of the abundances for the yields. Similarity of the endmembers to photosynthetic pigment’s spectral signatures and their predictive power suggests their relevance to the pigments. Although the initial unmixing of the intimate mixture of photosynthetic pigments is linear, interactions of abundances are used in the optimization to handle the non-linearity using bilinear model. Wheat yields are estimated with abundances, their relevant interactions, agrometeorological parameters and vegetation indices using three machine learning algorithms. Harvester records from 142 fields are used as ground truth for performance assessment. The yields are estimated with 82% accuracy (RMSE = 22.51) when Random Forest algorithm is used with important parameters.

A new series of environment-friendly reddish inorganic pigments based on AFeO3 (A = Ln, Y) with high NIR solar reflectance

Environment-friendly pigments based on AFeO3 (A = La, Pr, Nd, Sm, Gd, Tb, Y or Yb) with high near-infrared (NIR) reflectance were synthesised by a coprecipitation method at 1200 °C. The Rietveld refinement analysis showed single-phase orthorhombic perovskite for all compositions. All pigments, which showed reddish hues, offered good colour stability after mixing these pigments in powder form with siloxane transparent paint and two different glazes. The powder–paint mixtures produced with GdFeO3, TbFeO3 and YFeO3 pigments have the highest NIR solar reflectance, reaching values of R = 50%. The temperature shielding studies conducted using TbFeO3 pigment–paint mixture for a roof coating yielded a reduction of 3.2 °C in comparison to a commercial pigment. Moreover, the glazes that were pigmented using GdFeO3, TbFeO3 and YFeO3 compositions also presented the most intense reddish colours. A study of the thermal and chemical stability of the pigment with the highest NIR solar reflectance showed good stability in both cases. The reddish pigments that were prepared can therefore be good candidates for use in different applications such as cool pigments or pigments for ceramic glazes at high temperatures.

Anti-fatigue activity of gardenia yellow pigment and Cistanche phenylethanol glycosides mixture in hypoxia

The plateau, which has a unique geographical environment, forms extremely harsh climate conditions. Compared with that of people in the plains, the athletic ability of people on the plateau is significantly decreased. People who enter the plateau from the plains for short time periods will suffer from metabolic dysfunction, productivity loss, bradykinesia and a significant decrease in overall exercise endurance, which results in exercise fatigue. To investigate the anti-fatigue activity of gardenia yellow pigment and Cistanche phenylethanoid glycosides mixture under hypoxia, we performed anti-hypoxia, normoxia anti-fatigue and hypoxia anti-fatigue experiments. The gardenia yellow pigment and Cistanche phenylethanoid glycosides mixture has good anti-hypoxia and anti-fatigue effects under hypoxia, can significantly prolong the anti-anoxia time of mice, and prolong the exhausted swimming time of mice under normoxic and hypoxic conditions. The mechanisms may be related to reducing the accumulation of bad metabolites, increasing energy reserves, improving free radical scavenging capacity, increasing related metabolic enzymes activities, reducing apoptosis and inhibiting the infiltration of inflammatory cells. The gardenia yellow pigment and Cistanche phenylethanoid glycosides mixture is a potential functional product to improve hypoxic exercise fatigue.

Effect of Lining Papers on the Permanence of Painting Papers in Japanese Scroll Paintings During Moist Heat Ageing

ABSTRACT A Japanese painting paper is sized with an aqueous solution of alum and animal glue followed by brushing with a mixture of pigments of various colours and aqueous animal glue solution. Subsequently, to mount the Japanese painting to a hanging scroll, the backside of the painting is lined with a first lining paper using wheat starch paste for mechanical support. To evaluate the permanence of the painting paper as a composite material in the hanging scroll, the deterioration behaviour of the unlined painting paper and the lined painting paper was compared considering the material dynamics. After moist heat accelerated ageing (80°C, 65% RH), in the sample immersed in a CuSO4・5H2O solution, cellulose was oxidised by Cu2+ to generate organic acids in the painting paper, and Cu2+ and organic acids migrated to the lining paper. Consequently, the discolouration and oxidation of the painting paper in the lined complex were relatively low compared with those of the unlined painting paper. The pH decrease in the painting paper was also small in the lined complex. Moreover, if the animal glue solution was coated on the painting paper, a buffer effect was shown to operate against the organic acids derived from the oxidation of Cu2+, thereby inhibiting the migration of Cu2+ into the lining paper. In conclusion, the presence of the lining paper inhibited the decrease in the physical strength and degree of polymerisation of the cellulose in the painting paper, thus contributing to its permanence in the lined hanging scroll.

Ochre-Based Pigments in the Tablinum of the House of the Bicentenary (Herculaneum, Italy) between Decorative Technology and Natural Disasters

Ochre-based pigments have been employed since the first artistic expressions of mankind, with widespread diffusion during the Roman civilization. Such prominent use influenced their technological development, focused on functional and aesthetic optimization through complex manufacturing procedures. Furthermore, their appearance is also influenced by degradation processes, sometimes driven by natural disasters such as the eruption of Mount Vesuvius in 79 AD, in which yellow ochres of Vesuvian sites were sometimes converted to red by thermal alteration. In this contribution, a multi-analytical approach was adopted based on preliminary non-invasive investigations complemented by laboratory analyses to characterize the painted surfaces of the tablinum of the House of the Bicentenary (Herculaneum) with a particular focus on the ochre-based monochrome backgrounds. The study was aimed at (a) reconstructing the original color scheme of the walls and (b) deciphering the complex decorative techniques adopted by Roman craftsmen. The analytical results allowed testing and defining analytical procedures for the discrimination between the original and converted red pigments. Furthermore, these studies indicated that specific decorative technologies were adopted according to aesthetic, functional, and economic purposes, including the utilization of various qualities of ochre with different compositional and textural properties, and the mixture of ochre pigments with other compounds.

Исследование славянского пергамена методами спектроскопии комбинационного рассеяния света и люминесцентной спектроскопии

In the present article the pigments palette of a parchment handwritten fragment from the collection of Finnish fragments N 29 (Library of the Russian Academy of Sciences, Finnish fragment 29, old code - 4.9.28), dating from the XIV century, was investigated. This manuscript has not been restored earlier. With the aid of Raman spectroscopy technique it was found the use of cinnabar for red shades, the mixture of indigo and gypsum pigments in various ratios for blue shades and a mixture of sulfur-arsenic pigments (orpiment and pararealgar) for yellow shades. It was performed the study of the characteristic luminescence detection capability of the pigments at the real (non-model) samples, when excited by laser radiation of various wavelengths.

Four new Micarea species from the montane cloud forests of Taita Hills, Kenya

AbstractThe genus Micarea was studied for the first time in the Taita Hills, Kenya. Based on new collections and existing data, we reconstructed a phylogeny using ITS, mtSSU and Mcm7 regions, and generated a total of 27 new sequences. Data were analyzed using maximum likelihood and maximum parsimony methods. Based mainly on new collections, we discovered four undescribed well-supported lineages, characterized by molecular and phenotypic features. These lineages are described here as Micarea pumila, M. stellaris, M. taitensis and M. versicolor. Micarea pumila is characterized by a minutely granular thallus, small cream-white or pale brownish apothecia, small ascospores and the production of prasinic acid. Micarea stellaris has a warted-areolate thallus, cream-white apothecia usually darker at the centre, a hymenium of light grey or brownish pigment that dissolves in K, and intense crystalline granules that appear as a belt-like continuum across the lower hymenium when studied in polarized light. Micarea taitensis is characterized by a warted-areolate thallus and cream-white or yellowish apothecia that sometimes produce the Sedifolia-grey pigment. Micarea versicolor is characterized by a warted-areolate, sometimes partly granular thallus and apothecia varying from cream-white to light grey to blackish in colour. This considerable variation in the coloration of its apothecia is caused by an occasional mixture of the Sedifolia-grey pigment in the epihymenium and another purplish brown pigment in the hymenium. Micarea stellaris, M. taitensis and M. versicolor produce methoxymicareic acid. The main distinguishing characters are presented in a species synopsis. Three of the new species are nested in the M. prasina group, and the fourth one (M. taitensis) resolves as a basal taxon to the M. prasina group. The new species inhabit montane cloud forests, which have fragmented dramatically throughout the Eastern Arc Mountains in recent decades.

The cytotoxicity of cyclophosphamide is enhanced in combination with monascus pigment.

Monascus pigment is derived from red-mold rice fermented by monascus purpureus and utilized as a natural coloring agent and natural food additive in East Asia. Monascus pigment works as a radical scavenger. Some antioxidant combine cancer chemo­therapy to protect normal tissue because chemotherapy induce side effect for normal tissue. This combination therapy can attenuate the cytotoxicity of anti­cancer drugs by antioxidants effects. However, the effect of this combination therapy for cancer cells dose not investigate enough. In this study, we investigated the combination effect of anti­oxidants and anti­cancer drugs. We selected an anti­oxidant as monascus pigment and following four anti­cancer drugs: doxorubicin, tamoxifen, paclitaxicel, and cyclophosphamide. Combination treatment with monascus pigment and cyclophosphamide enhanced the cytotoxicity of cyclophosphamide. Moreover, this combination treatment accelerated apoptosis. The spot on TLC assay board of the monascus pigment and cyclophosphamide mixture is different from the spot of monascus pigment alone and cyclophosphamide alone. The interaction between monascus pigment and cyclo­phosphamide can produce some cytotoxicity compounds or accelerate intracellular cyclophosphamide accumulation. Hence, we concluded that the interaction of both cyclophosphamide and monascus pigment involved enhancement of cyclophosphamide cytotoxicity.